In video transmission over digital networks, various applications (in a broad area ranging from video conferencing to digital home theatre systems) require a sufficient level of responsiveness (i.e. low latency).
Conventional solutions have focused on reducing the transmission time (mainly by transmitting compressed data representing the video) and by trying to make this transmission time more predictable, for instance despite the variable amount of compressed data to be transmitted depending on the complexity of the images forming the video, and taking into account the limitations of the transmission channel.
A conventional solution to absorb jitter is to insert buffers (usually called “leaky buckets”) at various points on the video processing chain where congestion is expected, basically at the level of the encoder output and at the level of the transmission channel.
The use of buffers however tends to increase latency, which moreover remains unpredictable as it depends on network conditions and on image complexity.
This problem has been addressed in U.S. Pat. No. 6,937,653 by monitoring buffer occupancy and controlling it by either padding (i.e. filling with unused data) or deleting data in excess, which however significantly decreases the quality.